1. Field of the Invention
The present invention relates to a vibration generation device.
2. Description of the Related Art
A vibration generation device, a component that converts electrical energy into mechanical vibrations by using a principle of electromagnetic force generation, is mounted in a cellular phone to be used for silently informing a user of call receipt.
Further, there is growing demand for multi-functional cellular phones as the market for cellular phones rapidly expands. Since demand for small, high-quality cellular phone components is increased according to the expanded market for cellular phones, demand for product development of a vibration generation device having a new structure having remarkably improved quality while improving on defects of existing products has increased.
As a release of cellular phones having a large LCD screen has suddenly increased in recent years, a vibration generation device for generating vibrations at the time of a touch has been adopted due to the use of a touchscreens.
First, the vibration generation device used in a cellular phone in which a touchscreen is adopted is more frequently used to generate vibrations than merely at the time of call reception, and therefore, the operational lifespan of the vibrator needs to be increased. Second, the vibration generation device needs to have a rapid response speed, keeping pace with a user's speed of touching a touchscreen.
A cellular phone currently adopting a touchscreen uses a linear vibrator according to the demand for extended lifespan and responsiveness.
The linear vibrator does not use a rotation principle of a rotary motor, but may linearly resonate a mover connected to a spring by using a weight body connected with an elastic member mounted within the vibrator, using the electromagnetic force of a coil and a magnet to generate vibrations.
Further, vibrations may be generated by linearly resonating a mover according to the contraction and expansion of a piezoelectric element used as an actuator.
In addition, a spring has been generally used as the elastic member. Here, as the spring, a leaf spring, a coil spring, or the like, has been used. However, the lifespan of the spring may be limited due to a rupture thereof or the like. Further, when physical properties of the spring are changed due to a climatic environment, or the like, the spring may be more easily ruptured.
In addition, vibration force may be weakened or noise may occur at the time of occurrence of an abnormal operating mode (torsion, left and right shaking, and the like) of the spring.